The Change in Yield and Fruit Quality of Tomato as Affected by Groundwater Depth and Salinity in Coastal Regions

Abstract

【Objective】 Groundwater level in coastal saline-alkaline areas changes frequently due to the impact of tides. The associated water and salt movement in soil is hence more complicated than in other regions. This paper investigated the impact of groundwater depth and salinity on yield and fruit quality of tomato. 【Method】 The experiment was conducted in soil columns, with the groundwater table controlled at the depths of 90, 70, and 50 cm, respectively. Groundwater salinity was mimicked by NaCl concentration, which was controlled at 0, 2 and 4 g/L respectively. In each treatment, we measured the yield and fruit quality of the tomato. The treatments were compared using the principal component analysis and evaluation. 【Result】 The tomato yield, harvest index, average fruit weight and color index all decreased significantly with the increase in groundwater salinity, while increased significantly with the increase in groundwater depth. These four indexes were maximized when the groundwater depth was 90 cm and the NaCl concentration was zero. In contrast, vitamin C, soluble sugar, total acid and soluble solid content all increased significantly with the increase in groundwater salinity, while decreased significantly with the increase in groundwater depth. These four indicators peaked when the groundwater depth was 50 cm and NaCl concentration was 4 g/L. 【Conclusion】 Comprehensive principal component analysis shows that the comprehensive quality of the tomato increased with groundwater depth and decreased as the groundwater salinity increased. The optimal for our experiment was groundwater depth is 90 cm and the NaCl concentration is zero.

Keywords

• groundwater depth
• soil salinity
• tomato
• principal component analysis and evaluation